Abstract

This study aimed to encapsulate citral in chitosan nanoparticles and test its antifungal activity, along with the nanoparticles, against Fusarium oxysporum f.sp. lycopersici (FOL), a soil-borne pathogen causing worldwide yield losses in tomato production. The nanoparticles were characterized using scanning electron microscopy (SEM), FT-IR, encapsulation efficiency (EE), loading capacity (LC), and in vitro release pattern. SEM images revealed a spherical morphology with particle sizes ranging from 33 to 301 nm. EE and LC ranged from 2.9 to 7.2% and from 0.6 to 1.3%, respectively. The in vitro release exhibited a controlled pattern. Citral completely inhibited FOL mycelial growth at 500 µg/mL, with MIC/MFC determined at 512 µg/mL, whereas the nanoparticles achieved maximum mycelial inhibition (27%) at 1000 µg/mL, with MIC at 4096 µg/mL. Our study reveals citral as a potent biofungicide against FOL; however, further research is required to assess its in vivo activity. Increasing concentrations of the nanoparticles and the addition of copolymers to the chitosan-tripolyphosphate system for encapsulation of citral may enhance its potential for use as an antifungal agent.

Key words: Chitosan, nanoencapsulation, citral, antifungal, Fusarium oxysporum f.sp. lycopersici.